private static float MeasureClearance(out bool skip, Ray2 sideLine, Vector2 point, LineSegment2 edgeSeg, Vector2 edgeDir)
{
var startSegPoint = edgeSeg.ClosestPoint(point);
var sidePoint = new Ray2(startSegPoint, edgeDir.Perpendicular()).Intersects(sideLine);
if (!sidePoint.HasValue)
{
skip = true;
return(0);
}
skip = false;
return(sidePoint.Value.DistanceAlongA);
}
public static IEnumerable <Section> Sections(this IReadOnlyList <Vector2> outer, float width, out Vector2[] innerArr, out IReadOnlyList <IReadOnlyList <Vector2> > corners)
{
Contract.Requires(outer != null);
Contract.Requires(width > 0);
Contract.Ensures(Contract.Result <IEnumerable <Section> >() != null);
innerArr = outer.Shrink(width, 1).ToArray();
//Sanity check if shrinking has deleted the room!
if (innerArr.Length == 0)
{
corners = new IReadOnlyList <Vector2> [0];
return(Array.Empty <Section>());
}
//Create a place to put the results
var results = new List <Section>(innerArr.Length * 2);
//loop over segments of inner array
//inner array length is always <= outer array length
for (var i = 0; i < innerArr.Length; i++)
{
var a = innerArr[i];
var b = innerArr[(i + 1) % innerArr.Length];
var innerSegment = new LineSegment2(a, b);
//find a parallel segment which we can project the inner segment onto completely
float aT;
float bT;
var outerSegmentIndex = FindOuterSegment(innerSegment, width, outer, out aT, out bT);
if (outerSegmentIndex == -1)
{
continue;
}
var outerSegment = new LineSegment2(outer[outerSegmentIndex], outer[(outerSegmentIndex + 1) % outer.Count]);
//Clamp into the valid range
var adjustedAT = aT.Clamp(0, 1);
var adjustedBT = bT.Clamp(0, 1);
//Calculate the locations of the adjusted points
var aP = outerSegment.LongLine.PointAlongLine(adjustedAT);
var bP = outerSegment.LongLine.PointAlongLine(adjustedBT);
//Now adjust the inner points to match the adjusted outer points
var innerStart = innerSegment.Start;
if (Math.Abs(adjustedAT - aT) > float.Epsilon)
{
innerStart = innerSegment.ClosestPoint(aP);
}
var innerEnd = innerSegment.End;
if (Math.Abs(adjustedBT - bT) > float.Epsilon)
{
innerEnd = innerSegment.ClosestPoint(bP);
}
results.Add(new Section(innerEnd, innerStart, aP, bP));
}
//Calculate corner sections
corners = CalculateCorners(outer, width, results);
return(results);
}